#2930: Bug in QuasiLocalMeasures
Reporter:Marco Brito
Status:new
Milestone:
Version:
Type:bug
Priority:major
Component:EinsteinToolkit thorn

I found a bug in the QuasiLocalMeasures thorn, in the computation of the ADM momentum. In the source code file qlm_analyse.F90, in line 361 there is a plus sign instead of a minus sign, contradicting the ADM momentum formula: P^i_{ADM} = \frac{1}{8\pi}\lim_{r\to\infty} \oint_S (K^i_j - \delta^i_j K)dS^j [1]

As expected for slices where K \neq 0 one was getting a wrong result. The correction is easy, just replace the plus sign by a minus sign. You can find the corrected file in attachment.

[1] M. Alcubierre, Introduction to 3+1 Numerical Relativity, International Series of Monographs on Physics (Oxford University Press, Oxford, 2008).

attachment:qlm_analyse.F90

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2930/bug-in-quasilocalmeasures